The present invention relates in general to testing and diagnosis of internal combustion engines.
The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.
The use of compressed air to pressurize the combustion chamber of an internal combustion engine in order to determine the existence of a leak therein, is already known in the art. However, such leak detection method does not identify location of the leak. As to the diagnosis of engine condition throughout in order to schedule preventive maintenance, costly and labor intensive procedures were heretofore involved, often requiring engine disassembly. It is therefore an important object of the present invention to provide for complete and accurate condition diagnosis of an internal combustion engine with respect to leakage defects without costly and labor intensive engine disassembly.
In accordance with the present invention, operation of an internal combustion engine is terminated by securing its crankshaft against rotation and maintain its intake and exhaust valves closed through timing control means during performance of a testing process instituted by injection of acompressed testing gas. Vacuum tubes are connected to the different sampling locations in the engine for detection of leakage of the testing gas therefrom in order to identify and locate engine defects corresponding to detection of the highest of the leakages at the sampled locations in the engine.